I have manually edited the code after npm install to make it work but every npm install breaks the app. I have debugged it to the point that I have found out that its broken only on the client side code and opened an issue:

So, when I import
//server side
import classNames from 'classNames' //camelcase works fine
import classNames from 'classnames' //lowercase works fine
//client side
import classNames from 'classNames'...

Now I need to deploy and my app won’t work. Tell me, what to do brothers.

I fixed it by changing ‘classNames’ into ‘classnames’ everywhere in my code. It’s weird because I had ‘classNames’ all the time during development and it worked fine. Then suddenly it started causing errors.